Performance Measure Summary - Chicago IL-IN There are several inventory and performance measures listed in the pages of this Urban Area Report for the years from 1982 to 2014. There is no single performance measure that experts agree says it all. A few key points should be recognized by users of the Urban Mobility Scorecard data. Use the trends The multi-year performance measures are better indicators, in most cases, than any single year. Examining a few measures over many years reduces the chance that data variations or the estimating procedures may have caused a "spike" in any single year. (5 years is 5 times better than 1 year.) Use several measures Each performance measure illustrates a different element of congestion. (The view is more interesting from atop several measures.) Compare to similar regions Congestion analyses that compare areas with similar characteristics (for example, population, growth rate, road and public transportation system design) are usually more insightful than comparisons of different regions. (Los Angeles is not Peoria.) Compare ranking changes and performance measure values In some performance measures a small change in the value may cause a significant change in rank from one year to the next. This is the case when there are several regions with nearly the same value. (15 hours is only 1 hour more than 14 hours.) Consider the scope of improvement options Any improvement project in a corridor within most of the regions will only have a modest effect on the regional congestion level. (To have an effect on areawide congestion, there must be significant change in the system or service.) Performance Measures and Definition of Terms Travel Time Index A measure of congestion that focuses on each trip and each mile of travel. It is calculated as the ratio of travel time in the peak period to travel time in free-flow. A value of 1.30 indicates that a 20-minute free-flow trip takes 26 minutes in the peak. Planning Time Index A travel time reliability measure that represents the total travel time that should be planned for a trip. Computed with the 95th percentile travel time it represents the amount of time that should be planned for a commute trip to be late for only 1 day a month. If it is computed with the 80th percentile travel time it represents the amount of time that should be planned for a trip to be late for only 1 day a week. A PTI of 2.00 means that for a 20-minute trip in light traffic, 40 minutes should be planned. Peak Commuters Number of travelers who begin a trip during the morning or evening peak travel periods (6 to 10 a.m. and 3 to 7 p.m.). "Commuters" are private vehicle users unless specifically noted. per Commuter A yearly sum of all the per-trip delays for those persons who travel in the peak period (6 to 10 a.m. and 3 to 7 p.m.). This measure illustrates the effect of traffic slowdowns as well as the length of each trip. Total Delay The overall size of the congestion problem. Measured by the total travel time above that needed to complete a trip at free-flow speeds. The ranking of total delay usually follows the population ranking (larger regions usually have more delay). Free-Flow Speeds These values are derived from overnight speeds in the INRIX speed database. They are used as the national comparison thresholds. Other speed thresholds may be appropriate for urban project evaluations or sub-region studies. Excess Fuel Consumed Increased fuel consumption due to travel in congested conditions rather than freeflow conditions. Congestion Cost Value of travel delay for 2014 (estimated at $17.67 per hour of person travel and $94.04 per hour of truck time) and excess fuel consumption estimated using state average cost per gallon. Urban Area The developed area (population density more than 1,000 persons per square mile) within a metropolitan region. The urban area boundaries change frequently (every year for most growing areas), so increases include both new growth and development that was previously in areas designated as rural. Number of Rush Hours Time when the road system might have congestion.
Inventory Measures 2014 2013 2012 2011 2010 Population (1000s) 8,700 8,675 8,650 8,620 8,583 Commuters (1000s) 3,445 3,573 3,638 3,673 3,705 Freeway 57,279 56,433 55,380 62,791 60,800 Arterial Streets 79,284 76,308 48,145 51,500 49,326 Value of Time ($/hour) 17.67 17.39 17.14 16.79 16.30 Commercial Cost ($/hour) 94.04 89.60 89.56 86.81 88.12 Gasoline ($/gallon) 3.37 3.78 3.73 3.51 2.79 Diesel ($/gallon) 3.70 3.98 3.92 3.74 3.04 System Performance 2014 2013 2012 2011 2010 Congested Travel (% of peak VMT) 35 -- -- -- -- Congested System (% of lane-miles) 26 -- -- -- -- Congested Time (number of "Rush Hours") 4.70 -- -- -- -- Total Fuel (1000 gallons) 147,031 146,370 144,252 143,592 141,451 Fuel per Peak Auto Commuter (gallons) 29 29 29 29 28 Rank 5 4 4 4 4 Total Delay (1000s of person-hours) 302,609 301,248 296,890 295,531 291,125 Delay per Peak Auto Commuter (pers-hrs) 61 59 57 57 55 Rank 8 9 9 8 9 Travel Time Index 1.31 1.30 1.29 1.29 1.28 Rank 14 14 15 13 14 Commuter Stress Index 1.34 1.34 1.33 1.32 1.32 Rank 19 19 19 19 19 Freeway Planning Time Index (95th Pctile) 3.16 -- -- -- -- Rank 10 -- -- -- -- Total Cost ($ millions) 7,222 7,306 7,306 7,423 7,543 Cost per Peak Auto Commuter ($) 1,445 1,462 1,462 1,485 1,509 Rank 7 7 6 5 5
Inventory Measures 2009 2008 2007 2006 2005 Population (1000s) 8,519 8,460 8,440 8,420 8,400 Commuters (1000s) 3,670 3,632 3,616 3,601 3,579 Freeway 57,500 55,525 55,150 55,350 55,050 Arterial Streets 48,838 49,835 50,200 50,400 50,500 Value of Time ($/hour) 16.01 16.10 15.47 15.06 14.58 Commercial Cost ($/hour) 89.75 81.52 82.56 80.43 78.05 Gasoline ($/gallon) 2.31 3.58 3.24 2.73 2.34 Diesel ($/gallon) 2.63 4.24 3.52 2.93 2.58 System Performance 2009 2008 2007 2006 2005 Total Fuel (1000 gallons) 139,543 141,894 147,281 144,954 142,573 Fuel per Peak Auto Commuter (gallons) 28 28 29 29 29 Rank 4 4 4 4 4 Total Delay (1000s of person-hours) 287,198 292,037 303,123 298,334 293,434 Delay per Peak Auto Commuter (pers-hrs) 55 57 59 58 58 Rank 8 9 8 8 7 Travel Time Index 1.28 1.29 1.30 1.30 1.29 Rank 14 16 13 13 13 Commuter Stress Index 1.32 1.32 1.34 1.33 1.33 Rank 19 19 18 17 18 Total Cost ($ millions) 7,565 7,664 8,262 8,353 8,490 Cost per Peak Auto Commuter ($) 1,514 1,534 1,653 1,671 1,699 Rank 5 5 5 5 5
Inventory Measures 2004 2003 2002 2001 2000 Population (1000s) 8,340 8,275 8,210 8,150 8,090 Commuters (1000s) 3,534 3,487 3,433 3,337 3,242 Freeway 54,000 52,010 51,425 49,865 49,000 Arterial Streets 50,000 49,000 48,425 47,005 46,975 Value of Time ($/hour) 14.10 13.73 13.43 13.22 12.85 Commercial Cost ($/hour) 74.17 72.23 70.86 71.38 70.47 Gasoline ($/gallon) 1.95 1.57 1.46 1.50 1.70 Diesel ($/gallon) 2.03 1.56 1.43 1.62 1.60 System Performance 2004 2003 2002 2001 2000 Total Fuel (1000 gallons) 139,334 130,804 127,601 124,457 119,204 Fuel per Peak Auto Commuter (gallons) 28 26 26 25 24 Rank 4 4 4 3 3 Total Delay (1000s of person-hours) 286,768 269,213 262,619 256,150 245,337 Delay per Peak Auto Commuter (pers-hrs) 57 54 54 53 52 Rank 7 7 7 7 7 Travel Time Index 1.29 1.27 1.27 1.27 1.27 Rank 13 15 14 14 11 Commuter Stress Index 1.33 1.31 1.31 1.31 1.30 Rank 16 23 20 20 20 Total Cost ($ millions) 8,577 8,267 8,248 8,172 8,050 Cost per Peak Auto Commuter ($) 1,716 1,654 1,650 1,635 1,611 Rank 5 5 5 5 5
Inventory Measures 1999 1998 1997 1996 1995 Population (1000s) 8,075 8,060 7,950 7,880 7,745 Commuters (1000s) 3,172 3,102 2,997 2,908 2,797 Freeway 48,600 48,425 46,760 46,930 44,490 Arterial Streets 46,510 46,015 45,095 42,580 40,765 Value of Time ($/hour) 12.43 12.17 11.98 11.71 11.37 Commercial Cost ($/hour) 66.76 65.76 66.83 66.20 64.27 Gasoline ($/gallon) 1.17 1.15 1.21 1.39 1.28 Diesel ($/gallon) 1.17 1.21 1.30 1.48 1.36 System Performance 1999 1998 1997 1996 1995 Total Fuel (1000 gallons) 114,865 110,762 105,794 99,499 94,433 Fuel per Peak Auto Commuter (gallons) 23 22 21 20 19 Rank 4 4 3 4 4 Total Delay (1000s of person-hours) 236,408 227,963 217,739 204,782 194,357 Delay per Peak Auto Commuter (pers-hrs) 51 50 49 48 47 Rank 9 9 8 8 8 Travel Time Index 1.26 1.25 1.25 1.24 1.24 Rank 9 10 9 9 8 Commuter Stress Index 1.30 1.29 1.29 1.28 1.27 Rank 19 19 16 18 19 Total Cost ($ millions) 8,018 7,902 7,665 7,374 7,206 Cost per Peak Auto Commuter ($) 1,604 1,581 1,534 1,476 1,442 Rank 6 6 6 6 6
Inventory Measures 1994 1993 1992 1991 1990 Population (1000s) 7,700 7,600 7,515 7,515 7,510 Commuters (1000s) 2,726 2,636 2,553 2,500 2,445 Freeway 42,120 40,965 39,000 37,695 36,225 Arterial Streets 40,970 40,525 39,910 39,250 38,740 Value of Time ($/hour) 11.06 10.78 10.47 10.17 9.75 Commercial Cost ($/hour) 62.23 60.84 59.01 57.31 55.03 Gasoline ($/gallon) 1.11 1.16 1.19 1.19 1.16 Diesel ($/gallon) 1.18 1.23 1.26 1.30 1.19 System Performance 1994 1993 1992 1991 1990 Total Fuel (1000 gallons) 90,117 84,997 80,500 76,837 72,408 Fuel per Peak Auto Commuter (gallons) 18 17 16 15 14 Rank 4 4 4 6 5 Total Delay (1000s of person-hours) 185,472 174,935 165,680 158,141 149,025 Delay per Peak Auto Commuter (pers-hrs) 46 44 43 42 40 Rank 8 8 8 8 9 Travel Time Index 1.23 1.22 1.22 1.21 1.20 Rank 7 7 6 8 9 Commuter Stress Index 1.27 1.26 1.25 1.25 1.24 Rank 16 19 19 19 19 Total Cost ($ millions) 7,071 6,840 6,673 6,560 6,442 Cost per Peak Auto Commuter ($) 1,415 1,369 1,335 1,313 1,289 Rank 5 5 5 5 7
Inventory Measures 1989 1988 1987 1986 1985 Population (1000s) 7,405 7,330 7,240 7,195 7,150 Commuters (1000s) 2,387 2,345 2,294 2,257 2,225 Freeway 34,000 32,200 30,255 29,005 27,715 Arterial Streets 38,325 38,000 37,340 36,975 36,020 Value of Time ($/hour) 9.25 8.83 8.48 8.18 8.03 Commercial Cost ($/hour) 52.81 50.04 48.53 46.57 47.83 Gasoline ($/gallon) 1.13 1.04 1.05 1.02 1.34 Diesel ($/gallon) 1.07 0.99 0.99 0.97 1.27 System Performance 1989 1988 1987 1986 1985 Total Fuel (1000 gallons) 68,658 66,171 63,085 60,292 57,337 Fuel per Peak Auto Commuter (gallons) 14 13 13 12 11 Rank 5 5 4 5 5 Total Delay (1000s of person-hours) 141,307 136,189 129,836 124,090 118,006 Delay per Peak Auto Commuter (pers-hrs) 39 38 37 36 34 Rank 10 10 10 9 11 Travel Time Index 1.20 1.19 1.19 1.18 1.17 Rank 8 9 8 8 9 Commuter Stress Index 1.23 1.23 1.22 1.22 1.21 Rank 20 18 19 19 19 Total Cost ($ millions) 6,439 6,504 6,458 6,397 6,197 Cost per Peak Auto Commuter ($) 1,288 1,302 1,292 1,280 1,240 Rank 6 6 6 6 5
Inventory Measures 1984 1983 1982 Population (1000s) 7,100 7,100 7,080 Rank 3 3 3 Commuters (1000s) 2,187 2,171 2,142 Freeway 25,605 24,795 24,325 Arterial Streets 35,590 35,400 35,100 Value of Time ($/hour) 7.75 7.43 7.20 Commercial Cost ($/hour) 46.47 44.23 43.08 Gasoline ($/gallon) 1.35 1.38 1.44 Diesel ($/gallon) 1.28 1.31 1.37 System Performance 1984 1983 1982 Congested Travel (% of peak VMT) -- -- -- Congested System (% of lane-miles) -- -- -- Congested Time (number of "Rush Hours") -- -- -- Total Fuel (1000 gallons) 54,369 52,093 49,737 Rank 3 3 3 Fuel per Peak Auto Commuter (gallons) 11 10 10 Rank 3 4 4 Total Delay (1000s of person-hours) 111,900 107,214 102,365 Rank 3 3 3 Delay per Peak Auto Commuter (pers-hrs) 33 32 31 Rank 11 10 10 Travel Time Index 1.17 1.16 1.16 Rank 7 7 7 Commuter Stress Index 1.20 1.20 1.19 Rank 19 18 18 Freeway Planning Time Index (95th Pctile) -- -- -- Rank -- -- -- Total Cost ($ millions) 6,085 6,082 5,994 Rank 3 3 3 Cost per Peak Auto Commuter ($) 1,218 1,217 1,199 Rank 4 5 6